Catch a Falling Star
When a large meteor struck the earth some 65 million years ago, the event might well have been catastrophic enough to wipe out the dinosaurs, which then dominated the planet. In the last few years, Hollywood movies have dramatized the possibility that human beings could one day meet their own demise through a similar catastrophe. Are they right?
The less dramatic reality is that our world continues to be showered by material from outer space. These smaller meteors, called meteoroids or meteorites, are nowhere near the size of an object that could cause the extinction of a species. Nevertheless, we are only beginning to understand the nature of this astrophysical phenomenon. And now that we have sophisticated radar and satellite systems, and have even sent spacecraft to visit these bodies in space, our understanding is beginning to grow.
In the early 1990s, for example, the first detailed video record of a meteorite fireball made it possible to determine the orbit from which this object had fallen to earth. Peter Brown and his colleagues calculated this orbit—a computational feat that has been possible in only a handful of cases where a meteorite has been recovered.
As the holder of a Canada Research Chair, Brown intends to continue investigating the origins and physical features of meteors. He plans to develop computer models of how they might be distributed throughout the solar system. And he’ll use radar, sound, and satellite data to document actual examples of meteors arriving on earth.
This research will provide more reliable estimates of the number of meteors travelling near the earth that might be large enough to be seen by telescope. Brown also expects to measure the energy released—in the form of sound and light—as those meteors enter the atmosphere and strike the earth. In this context, he plans to more accurately consider the question of how large one of those meteors would have to be to cause significant damage if it struck the earth.